Dual showerhead adapter



FIG. 1 is a front elevational view of a dual showerhead adapter showing my new design;

FIG. 2 is a left side elevational view thereof, which is also a mirror image of the right side elevational view;

FIG. 3 is a top plan view thereof;

FIG. 4 is a back elevational view thereof; and,

FIG. 5 is a bottom plan view thereof. 

The ornamental design for dual showerhead adapter, as shown and described. 